But the premature birth of disturbances in the main development region of the Atlantic, and now Tropical Storm Don, has also been a past indicator of a busy storm season.

“It is unusual to have frequent disturbances in the main development reason in June and July, since ocean temperatures in that region still do not support development in most years,” said Todd Crawford, chief meteorologist for The Weather Company.

Colorado State University’s Tropical Meteorology Project is now forecasting an above average hurricane season for 2017.

The sea-surface temperatures, however, are unusually warm in the area of the tropics where storms typically don’t start appearing until August through October.

“All other things being equal, this is foreboding as we head into the heart of the season, and we do expect a relatively active season this year given the warm ocean waters,” Crawford said.

The typical areas for tropical cyclones to form in July.

Klotzbach’s updated hurricane forecast now calls for a total of 15 named storms, eight hurricanes and three major hurricanes. These numbers include the three tropical storms that formed prior to Don on Monday.

The average storm season has 12 named storms, 6 hurricanes, and 3 major hurricanes.

“Often, our July update doesn’t change, but this year we did up it because it is just looking more conducive for activity,” Klotzbach said. “Having a lot of these kinds of systems coming off and looking decent, that tends to be a sign for a nasty season.”

But there are always caveats, Klotzbach said. The 2013 season was forecast to be above average and it ended with only two hurricanes.

“The Atlantic is always on the edge of getting a lot, or getting a little,” Klotzbach said.

The typical formation area for tropical cyclones in August. This season, more disturbances and invests have been identified in this area in July.